MXPA04007648A

MXPA04007648A - Dynamic host configuration protocol lease time determination.

Info

Publication number: MXPA04007648A
Application number: MXPA04007648A
Authority: MX
Inventors: Lee Ryan David
Original assignee: Thomson Licensing Sa
Priority date: 2002-02-06
Filing date: 2003-02-05
Publication date: 2005-05-27
Also published as: AU2003210848A1; KR20040077888A; WO2003067837A3; WO2003067837A2; AU2003210848A8; JP2005517354A; CN1628444A; US20030147421A1; BR0302975A; EP1472839A2

Abstract

A method and apparatus for dynamic host configuration protocol lease time determination by receiving (402) at a first dynamic host configuration protocol device (310), a message requesting allocation of an IP address to a client (110), and allocating (408) to the requesting client (110) a relatively short lease time, if a second dynamic host configuration protocol device (320) does not contain the requested IP address lease.

Description

or 03/067837 A2? «??????????«? European patent (AT, BE, BG, CH, CY, CZ, DE, DK, EE, For two- tter codes and other abbreviations, please refer to the "Guid- ES, FI, FR, GB, GR, HU, IE, IT, LU, MC, NL, PT, SE, YES, ance Notes on Codes and Abbreviations "appearing at the beginning- SK, TR), OAPI patent (BF, BJ, CF, CG, CI, CM, GA, GN, no of each regular issue of the PCT Gazette, GQ, GW, ML, MR, NE, SN, TD, TG). Published: - withoui iniernational search report and to be republished upon receipt of that report METHOD AND DEVICE FOR DETERMINING TIME OF RENTAL OF A PROTOCOL WITH GUEST CONFIGURATION DYNAMIC CROSS REFERENCE WITH RELATED APPLICATIONS This application claims the benefit of United States Provisional Application Serial No. 60 / 355,665, filed on February 6, 2002, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION The present invention relates to the field of data networks and in particular to Dynamic Host Configuration Protocol (DHCP) revenues in data networks.

BACKGROUND OF THE INVENTION The Internet provides multimedia content including audio, video, graphics and text, which often require a bandwidth for downloading and viewing. Many Internet Service Providers (ISPs) allow their customers to connect to the Internet through a telephone line from a Public Switched Telephone Network (PSTN) at different speeds, including 14,400 bps, 28,800 bps and 56,000 bps. Cable television networks, on the other hand, are typically interconnected by cables, such as coaxial cables or Coaxial / Hybrid Fiber (HFC) cable systems, which have data rates of approximately 10 mega-bits-per-second (Mbps). ) at 30 + Mbps. These data rates are much higher than the data rates available in the PSTN. As a result of the rapid growth of the Internet, many users have started using broadband connections, such as that provided by cable modems, because they offer a wider bandwidth. In a typical network, such as the Internet, the use of a sub-network, or an Intranet, or a Dynamic Host Configuration Protocol (DHCP) is very common. Dynamic Host Configuration Protocol (DHCP) is a protocol that defines the method by which the server assigns Internet Protocol (IP) addresses to requesting clients for a defined period of time (known as rental time). The IP addresses are used by the devices of the client's equipment (CPE) to communicate with other devices that are connected to the network. One advantage of using DHCP to obtain IP addresses is that you can obtain other configuration information that is important to the network device, with a single message exchange. DHCP protocols are defined in a Request for Comments (RFC) RFC-2131 and RFC 2132, an Internet standards tracking protocol standardized by the Internet Engineering Task Force (IETF). An end network device such as a cable modem or router often contains a built-in DHCP server 3 that is used to provide PCs or other CPE devices with IP addresses that are in a sub-network isolated from the network. Wide Area Network (WAN). These CPE devices often need to have a WAN address for the exchange of information with other devices on the WAN side of the end network device. An example is the download of a network page, in which case the CPE device comes into contact with a domain name server (DNS) to convert the Internet name to an IP address. As such, the embedded DHCP server provides DNS and other WAN information to CPE devices. In addition to endpoint network devices that have built-in DHCP servers, they can also have a built-in DHCP client to obtain their own addresses that belong to the WAN subnetwork. After successfully obtaining an IP WAN the DHCP client, the client has the relevant information for the DHCP server incorporated as the DNS IP. A disadvantage associated with a DHCP as defined by RFC-2131 and RFC-2132 is that once the rent is granted by a DHCP server, the server has no opportunity to claim or change the rent until the client attempts to renew their rent. at a later time. This later time is the limit of the rental time granted in the acknowledgment of the DHCP server rental application, and may result in a delay or inactivity. For example, when the DHCP client has not been granted with a DHCP lease by a WAN server, the DHCP client does not have the information requested by the CPE and a lease by a DHCP server for the CPE will not be effective as the data requested are not present in the DHCP client and therefore can not be transferred.BRIEF DESCRIPTION OF THE INVENTION The invention comprises a method and apparatus for a rental time determination for a dynamic host configuration protocol (DHCP), so that inactivity is minimized and CPE devices obtain the WAN type information as soon as possible. as available. A method according to an embodiment of the invention for determining the DHCP lease time includes receiving a message in a first dynamic host configuration protocol (DHCP) requesting the hosting of an IP address of a client, and housing to the requesting client a relatively short rental time, when a second DHCP device does not contain the requested IP address rent. An apparatus in accordance with an embodiment of the invention for determining DHCP lease time includes a first DHCP device, to receive messages from the client's system and issue lease times to the client's system in response to messages, messages requesting the hosting of IP addresses, a second DHCP device for receiving the incomes of the IP addresses from a wide area network associated with the requested IP addresses, a memory for storing the parameters and communication instructions and a processor. The processor, after executing the instructions, is configured to receive in the first DHCP device a message requesting the accommodation of an IP address for a client and host the requesting client a relatively short rental time, when a second DHCP device does not contain the IP address rent requested.

BRIEF DESCRIPTION OF THE DRAWINGS The teachings of the present invention can be easily understood by considering the following detailed description together with the accompanying drawings. Figure 1 illustrates a high-level block diagram of an Internet network, which includes an embodiment of the present invention.

Figure 2 illustrates a high-level block diagram of a modality of a NAT device; suitable for use in the Internet network of Figure 1. Figure 3 illustrates a block diagram showing the process of moving a network address of the NAT device of Figure 1 and Figure 2, in accordance with the principles of the present invention. Figure 4 illustrates a flow chart of an exemplary method in accordance with the principles of the present invention. 6 To facilitate understanding of them, identical reference numbers have been used to indicate identical elements that are common in the Figures.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described within the context of a network of computers and associated devices connected to the Internet. However, those skilled in the art will appreciate that the present invention can be employed with advantages in any communications system with the use of a dynamic host configuration protocol (DHCP). In this way, it is contemplated that the present invention has wide application beyond the network systems described herein. Figure 1 illustrates a high-level block diagram of a network 100 including an exemplary embodiment of the present invention. Network 100 of Figure 1 comprises a plurality of computer equipment devices (CPE) (illustratively two personal computers (PCs) 1101 and 1102, collectively PC 110), a plurality of end network devices (illustratively a plurality). of cable modems (C) 1201-120HN, a cable modem termination system 130 (CMTS) and the Internet 140. The two PCs 110 comprise a local area network and the Internet 140 comprises a wide area network (WAN) The WAN also comprises a 150 WAN DHCP server.Also, each of the CM 1201-120N of Figure 1 comprises a 751-125N network address (NAT) transfer device.The NAT devices 1251 -125N provide IP addresses and configuration parameters for the camera between the LAN and the WAN, although in Figure 1 the NAT 1251-125N devices are illustrated incorporated within the CM 1201-120N, those skilled in the art will be able to recognize that NAT 1251-125N devices can be incorporated into other end-network devices such as routers. Alternatively, the 1251-125N Nat devices may comprise separate units cooperating with the CM 1201-120N. During an upstream transmission, a DHCP rental request (IP rental request) is generated on the LAN (ie, by a PC 110). The DHCP rental request is communicated to its respective CM 120. The CM 120 modulates the signal from the PC 110 for upstream communication through a cable transport network (CT). The CM 120 also acts as an identifier or relay agent which is associated by the Internet 140 for communications with the particular LAN devices (PC 110). The 125 NAT device of the CM 120 provides an Internet protocol (IP) address for upstream communication to the Internet 140. The IP address provided by the 125 NAT device includes all relevant fields / parameters necessary for communication with the Internet 140. In general, the list of parameters includes server IP addresses of the domain name (DNS) and domain name. The operation of NAT 125 will be described in more detail below. The C TS 130 receives the signals from the C 120 and converts these signals into IP packets (if they are not already formed), which it starts to send to an IP router (not shown) for transmission through the Internet 140. During Downstream transmission, information from the Internet 140 is received by the CMTS 130. The CMTS 130 modulates the downstream signals for transmission through the CT network. The CM 120 demodulates the downstream signal. The NAT 125 device within the CM 120 provides an IP address for communication with the requesting PC 110. The operation of the 125 NAT device will be described in more detail below. Figure 2 illustrates a high-level block diagram of a modality of a NAT device suitable for use in the Internet network of Figure 1. The NAT 125 device of Figure 2 comprises a processor 210 as well as a memory 220 for storing algorithms and control programs. The processor 210 cooperates with conventional support circuitry 230 such as power supplies, clock circuits, cache memory and its like, as well as circuits cooperating to execute the routines of the software stored in the memory 220. As such, it is contemplated that some of the steps of the process described herein as the software processes can be implemented within the hardware, 9 for example, as the circuitry cooperating with the processor 210 to carry out several steps. The NAT 125 device also includes input-output circuitry 240 that forms an interface between the different elements communicating with the 125 NAT device. For example, in the embodiment of Figure 1, the NAT device 125 communicates with the PCs 110 through a signal path S1 and with the Internet 140 through a signal path 01. Although the device 125 NAT of Figure 2 is illustrated as a general-purpose computer that is programmed to perform various control functions in accordance with the principles of the present invention, the invention can be implemented in the hardware, for example, as an application of a specific integrated circuit (ASIC). As such, the steps of the process described herein are intended to be broadly interpreted as being carried out in an equivalent manner by the software, hardware or a combination thereof. Further, although the NAT 125 device of Figure 2 is illustrated as a general purpose computer for carrying out various control functions in accordance with the present invention, the 125 NAT device can be incorporated as software within an existing computer of the device., such as a router or a cable modem, to be updated with the NAT feature. Figure 3 illustrates a block diagram illustrating an exemplary network address transfer process of the NAT device 125 in accordance with the principles of the present invention. The NAT device 125 of Figure 3 comprises a DHCP server 310 on the LAN side and a DHCP client 320 on the WAN side. The DHCP server 310 and the DHCP client 320 may be essentially computer programs or other permanent programs or software that implement the Dynamic Host Configuration Protocol (DHCP) defined in the Internet RFC-2131 and RFC 2132. These are incorporated herein by reference. its entirety With respect to functionality, the DHCP server 310 provides PCs 110 with IP addresses that are available on the LAN side, isolated from the WAN side. Similarly, the DHCP client 320 provides the IP addresses of the WAN devices for communication with the Internet 140. The CPE devices (i.e., the PCs 110), the DHCP servers (i.e. the DHCP server 310) and the devices. DHCP clients (that is, the DHCP client 320) communicate with the use of the DHCP protocol. The DHCP protocol uses the concept of an income for a period of time that the IP address is assigned (that is, the amount of time that the client's PC 110 uses to receive information from the Internet 140). When a DHCP lease request is communicated from the PC 110 to the DHCP server 310, the DHCP server 310 hosts the IP address for communication with the PC 110 and establishes a lease time for processing the DHCP lease request from the PC 110. In addition, the DHCP client 320 issues a rental request for an 11 IP address from the Internet 140 corresponding to the information requested by the PC 110. The 150 WAN DHCP server on the WAN side returns an appropriate IP address to the client 320 DHCP and it emits the rental time for the DHCP client 320 to know what the appropriate configuration parameters are (ie the DNS and the domain name parameters) to process the DHCP request from the PC 110. Although the NAT 125 device does Figure 3 illustrates a DHCP server 310 and the DHCP client 320 as two separate components, the DHCP server 310 and the DHCP client 320 may comprise a single computer or other systems that implement the DHCP but they work as two separate components. When a LAN device CPE (PC 110) requests an income from the DHCP server 310 before the client 320 DHCP on the WAN side successfully obtains its own rent from the 150 WAN DHCP server, to know the relevant DNS IP and the parameters of the domain name to be transferred to PC 110, long rental time granted by the DHCP server 310 to the requesting PC 110 will result in a long period of inactivity for the requesting PC 110. That is, because the client 320 on the WAN side has not obtained the appropriate information required by the requesting LAN CPE device, the WAN type information required by the requesting LAN CPE device can not be provided by the DHCP 320 during the rental time. granted by the DHCP server 310 and therefore, the 12 rental time granted will not be effective and therefore will be wasted. In one embodiment of the present invention, a method for resolving the disadvantages of the DHCP server 310 that grants long rental times to the requesting PC 110 before the DHCP client 320 receives the lease grant from the DHCP server 150, comprises the that the DHCP server 10 grants short rental times to the requesting PC 110 until the client 320 DHCP on the WAN side obtains its WAN rental time and contains the associated IPs and the configuration parameters. Short refers to tens of seconds in length, as opposed to the tens of thousands of seconds in length usually associated with conventional rental times. For example, a conventional long rental time is typically greater than ten thousand seconds (i.e., 15000 seconds) and the relatively short rental times in accordance with the present invention are less than one thousand seconds (i.e., 100 seconds). However, due to the wide application of this concept, it can be established that a relatively short rental time is any rental time less than an arbitrary period of time T. Similarly, a relatively long rental time can be considered. is any rental time greater than an arbitrary period of time T. In the CM 120, the DHCP server 310 assumes that when the DHCP client 320 has obtained a valid IP rental, the DHCP client 320 has a group of network information that goes to obtain. In this way, with a CPE device rental request (PC 110), the DHCP server 310 requests the DHCP client 320 to determine when the DHCP client 320 has a valid own IP rental. When the DHCPP server 310 finds that the DHCP client 320 has a valid rent, it grants longer rental times (in the order of thousands of seconds or more) to the requesting PC 110. During the long rental times, the server 310 transfers the relevant information such as DNS IP and domain names to the requesting PC 110, when the DHCP client 320 has such information. When the DHCP client gets a valid rent, but the network information is not known such as DNS IP or domain name, the DHCP server 310 proceeds with a longer rental time, assuming that the DHCP client will not return such parameters. When the DHCP client 320 does not have a valid IP rental at the time of the DHCP lease request from PC 110, the DHCP server 320 responds with a short lease time. The CPE devices (PC 110) will renew their revenues frequently, so that when the DHCP client 320 obtains its rent from the 150 WAN DHCP server, the relevant WAN parameters and information are immediately transferred to the 310 DHCP LAN server. As a result of the shorter rental times granted by the DHCP server 310 to the requesting PC 110, the inactivity period of the PC 110 is minimized. In addition, the period of time that the assigned particular IP address is not available 14 for the requesting PC 110 by the DHCP server 310 is also reduced. That is, because the IP address is owned by the client between the income recognition and the rent renewal by the client (PC 110), a shorter rental time will result in shorter periods of unavailability for an assigned IP. Figure 4 illustrates a flow chart of one embodiment of a method of the present invention. Method 400 is introduced in step 402 when the DHCP server receives a DHCP lease request from the CPE device. In step 404, the DHCP server determines whether the corresponding DHCP client has received its own IP WAN rent. When the DHCP client has received its own IP WAN rent, method 400 proceeds to step 406, when the DHCP client has not received its own IP WAN rent, the method proceeds to step 408. In step 406, the DHCP server offers the requesting CPE device a relatively long rental time and delivers the required WAN parameters as the DNS IP to the requesting CPE device. That is, the DHCP server assumes that when the DHCP client has obtained a valid IP lease, the DHCP client has a group of network information that it will get later. As such, the DHCP server offers the requesting CPE device a relatively long rental time and delivers the required WAN parameters such as the IP DNS to the requesting CPE device. Method 400 is terminated and the DHCP server waits for another DHCP lease request from the CPE device. In step 408, the DHCP server offers the requesting CPE device a relatively short rental time. That is, when the DHCP client does not have a valid IP income at the time of the DHCP lease request from the CPE, the DHCP server responds with a short rental time granted to the requesting CPE. The CPE (PC) devices will renew their rents so that the DHCP client obtains a rent from the DHCP WAN server, the relevant WAN parameters and the information are immediately transferred to the DHCP server and then to the requesting CPE. Method 400 terminates and the DHCP server waits for another DHCP lease request from the CPE device. This description is directed to some embodiments of the present invention, other embodiments of the invention are contemplated without departing from the basic scope thereof. As such, the scope of the invention is determined in accordance with the claims.

Claims

16 CLAIMS 1. A method characterized in that it comprises: receiving in a first device (310) a dynamic host configuration protocol (DHCP), a message requesting the hosting of an IP address for a client; and accommodating the requesting client (110) a rental time less than the period T of time when a second device (320) has not obtained the requested accommodation of the IP address. The method according to claim 1, characterized in that it further comprises: housing (310) the requesting client with a rental time greater than the period T of time when the second device (320) DHCP has obtained the requested accommodation of the IP adress. 3. The method according to claim 2, characterized in that the period T of time is greater than ten thousand seconds. 4. The method according to claim 1, characterized in that the period T of time is less than one thousand seconds. The method according to claim 1, characterized in that the first DHCP device (310) comprises a DHCP server. 6. The method according to claim 1, characterized in that the second DHCP device (320) comprises a DHCP client. The method according to claim 1, characterized in that the message is a DHCP lease request. The method according to claim 7, characterized in that the IP address also comprises an IP address of the domain name server (DNS) and the name of the domain associated with the requested IP address. 9. An apparatus (125) characterized in that it comprises: a first DHCP device (310) for receiving messages from the client (110) and issuing rental times to the client (110) in response to messages, messages requesting accommodation of an IP address for a client (110); a second device (320) for receiving IP address rents from a wide area network (140) associated with the requested IP addresses; a memory (200) for storing the parameters and communication instructions; and a processor (210) that after executing the instructions, is configured to: receive in a first DHCP device (310) a message requesting the accommodation of an IP address for a client (110); and 18 granting the customer (110) a rental time less than the period T of time when the second device (320) has not obtained the requested accommodation of the IP address rent. The apparatus (125) according to claim 9, characterized in that the first DHCP device (310) comprises a DHCP server. The apparatus (125) according to claim 9, characterized in that the second DHCP device (320) comprises a DHCP client. The apparatus (125) according to claim 9, characterized in that the apparatus is incorporated into an end network device (120). The apparatus (125) according to claim 12, characterized in that the end network device (120) is a cable modem. The apparatus (125) according to claim 12, characterized in that the end network device (120) is a router. 15. A computer readable medium for storing a group of instructions, wherein when the group of instructions is executed by the processor, the method comprising: receiving in a first device (310) (DHCP) configuration protocol is carried out. dynamic host a message requesting the accommodation of an IP address to the client (110); and 19 granting a requesting client (110) a rental time less than the period T of time when a second device (320) DHCP has not obtained the requested accommodation of the IP address. 16. An apparatus characterized in that it comprises: means for receiving in a first device (310) (DHCP) a dynamic host configuration protocol, a message requesting the accommodation of an IP address for a client (110); and means for granting a requesting client (110) a rental time less than the period T of time when a second (320) DHCP has not obtained the requested accommodation of the IP address.